Cephalopod Awareness Days: Cuttling Up to Cuttlefish and Squid
Greetings Blogophiles! Welcome to day three of Cephalopod Awareness Days. Today, October 10th, is the day we celebrate the cephalopods with ten appendages; squid and cuttlefish. Woo Hoo! Finally a subject I actually do research on. Because of that, I celebrate squid and cuttlefish almost daily. But rather than rehash the year and a half my colleagues and I spent monkeying about with chitin in Eocene cuttlebones or the big Cretaceous squid project. Today I’ll focus on calamari. Oh wait…that’s dinner; back to blogging.
So, squid and cuttlefish; most people are aware of squid. They show up in our lives as calamari (yes, I am hungry) or as bait. If you happen to be training to become a neurosurgeon you would practice your skills on squid axons because they are much thicker than axons in the human brain, yet they are morphologically and functionally similar. Squid axons are also being used to study the role environmental toxins may play in Parkinson’s disease.
People tend to be less aware of cuttlefish. But that doesn’t mean they are any less interesting. If you’ve never seen “Kings of Camouflage” on PBS, I highly recommend you take the hour to watch it. You’ll be glad you did.
Here are some fast facts:
- Both squid and cuttlefish have eight arms and two tentacles
- Both squid and cuttlefish have internal shells. Squid have a gladius, or pen, which in extant squid is made of chitin. Cuttlefish have a cuttlebone, made of the mineral aragonite and chitin.
- Squid can and do inhabit very deep water. Because of their mineralized cuttlebones and other factors cuttlefish generally live in shallower waters. If they were to dive too deep too rapidly their cuttlebones would break under the pressure.
- Cuttlebones are given to pet birds as a source of calcium.
- Both squid and cuttlefish can move using jet propulsion. Some species of squid are even known to fly for short distances.
- Both squid and cuttlefish have chromatophores in their skin that allow them to rapidly change color.
- Artists once used cuttlefish ink as sepia.
- Most squid are no more than 6 meters long, however the giant squid (Architeuthis dux) and the colossal squid (Mesonychoteuthis hamiltoni) are much longer, up to ~14 meters.
- The largest colossal squid ever documented weighed in at 495 kilograms which is over 1000 lbs.
- Cuttlefish range in size from 15 cm to 25 cm. The largest species, can be up to 50 cm in mantle length and over 10.5 kg in weight.
- Cuttlefish are not found of the coast of the Americas today, but we do find fossil “cuttlebones” of extinct cuttlefish-like critters in Eocene sediments of North Carolina.
This list could go on and on, but you get the idea. So take today to celebrate our ten-appendaged compatriots and if you happen to see a cuttlefish or eat some squid, remember to be aware of just how fascinating these creatures are. Tune in tomorrow for day four of Cephalopod Awareness Days.